US Section 301, 232 and IEEPA tariffs explained

What "special tariffs" actually means

If you import into the United States, the duty rate printed against your product's tariff line is only the starting point. On top of that base rate, three separate trade-remedy programs can apply: Section 301, Section 232, and IEEPA tariffs. Each was created under a different law, for a different reason, and each is layered onto your shipment in addition to the ordinary customs duty — not instead of it.

This is the single most expensive thing importers get wrong. People look up a base rate, plug it into a landed-cost calculator, and budget accordingly — then the customs entry comes back two or three times higher because a 301 or 232 measure stacked on top. Understanding how these tariffs work, and where to confirm the current numbers, is the difference between a profitable order and a loss.

They stack additively on the same customs value

The mechanics are straightforward once you see them. All of these tariffs are assessed on the customs value of your goods — for the US, that's the transaction value on an FOB basis (international freight and insurance to the US are excluded from the duty base; see CIF vs FOB). The base HTS duty and each applicable special tariff are calculated against that same value and then summed.

So if a product carries a base HTS duty, a Section 301 China-origin tariff, and a Section 232 measure, you don't compound them on top of one another — you add each percentage to the same base and total them. The effective rate is the sum of the parts. A line item that looks like a modest base duty can become a serious number once one or two trade-remedy layers are added.

Because the layers add rather than replace, the order you apply them in doesn't change the duty total — but it absolutely changes your total versus a naive estimate that only counted the base rate.

Section 301 — country-of-origin trade actions

Section 301 of the Trade Act of 1974 lets the US Trade Representative act against foreign trade practices it deems unfair. In practice, the program most importers deal with is the action against China-origin goods: large lists of HTS subheadings carry an additional duty when the country of origin is China.

Two things matter here. First, country of origin drives everything — not where you bought the goods or where they shipped from. Goods of Chinese origin trans-shipped through a third country are still China-origin for 301 purposes; substantial transformation in another country is a complex, fact-specific question, and customs polices it hard. Second, 301 is list-based and HTS-specific: whether your product is covered, and at what additional rate, depends on its exact tariff classification appearing on a covered list. Getting the HS/HTS classification right is therefore not just about the base rate — it determines your 301 exposure too.

Section 232 — steel, aluminum and national security

Section 232 of the Trade Expansion Act of 1962 authorizes tariffs on imports judged to threaten national security. The long-standing and most familiar 232 measures cover steel and aluminum and certain downstream products made from them. The scope has been extended over time to various derivative articles, so a finished good containing covered metal can be caught even if you don't think of it as "a steel product."

As with 301, 232 applies on top of the base duty and depends on the HTS code and, for some measures, the country of origin and any country-specific arrangements. If you import anything metal-intensive — fixtures, fasteners, tools, machinery parts, packaging — assume 232 might apply and verify before you commit to a price.

IEEPA tariffs — the newest and most volatile layer

The International Emergency Economic Powers Act (IEEPA) has more recently been used as the basis for additional tariffs tied to declared national emergencies. These IEEPA measures, again, add on top of the base HTS duty and any 301/232 already in play, and they have moved faster and more unpredictably than the older programs — rates, covered countries, and effective dates have shifted on short notice.

Treat IEEPA tariffs as the most fluid part of your calculation. A rate that was correct last month may not be correct today, and exclusions or changes can take effect with little lead time.

De minimis is gone — small parcels are now dutiable

For years, US importers leaned on the $800 Section 321 de minimis: low-value parcels cleared free of duty. That relief is suspended. Under Executive Order 14324 (effective 29 August 2025, with permanent statutory repeal scheduled for 1 July 2027), the de minimis exemption no longer applies for any country of origin.

The practical effect: US duty — including the special tariffs above — now applies from the first dollar. Do not assume a shipment under $800 is duty-free; that planning rule is no longer valid. A small e-commerce parcel of China-origin goods can now attract base duty plus a 301 add-on plus, potentially, an IEEPA layer, even on a low order value. If your model depended on de minimis, rebuild it. (More background in de minimis explained.)

Don't forget the federal fees

Special tariffs aren't the only add-ons. On a formal entry (customs value over $2,500), the Merchandise Processing Fee is 0.3464% of customs value, with a minimum of $33.58 and a maximum of $651.50 (FY2026); informal entries of $2,500 or less pay a small flat fee instead. Ocean shipments also pay the Harbor Maintenance Fee of 0.125% of customs value, with no cap. These are separate from duty and from the trade-remedy tariffs, and they belong in any honest landed-cost figure.

Note too that the US has no federal VAT or GST — there's nothing collected at the border the way import VAT works elsewhere. State sales or use tax is a separate domestic matter, not a customs charge.

How to get the right number — every time

Because 301, 232, and IEEPA rates change frequently and turn on the exact HTS code and country of origin, never rely on a percentage you remembered from a previous shipment. The workflow that keeps you out of trouble:

1. Classify the product precisely. The 10-digit HTS code determines the base rate and whether any special tariff list catches you. If you're unsure, a binding ruling from CBP removes the guesswork.
2. Confirm the country of origin — substantial transformation, not the shipping point.
3. Check the current measures on the USITC HTS and CBP for that exact code and origin: base duty, then any 301, 232, and IEEPA layers in force today, with their effective dates.
4. Add the applicable layers to the same customs value, then add MPF and (for ocean) HMF.
5. Re-check before each order, since the trade-remedy layers move.

When you have the current rates in hand, the US import duty calculator will sum the base duty, your special-tariff inputs, and the federal fees into a single landed-cost figure — but the accuracy of the output depends entirely on confirming those rates at the source first. The rates are the variable; the discipline of looking them up is the constant.